Photoacoustic evidence of target ablation for LPVD of YBCO thin films

In the case of complex processes related to the laser interaction with solid materials, elastic waves appear in the volume of the target and their waveforms and intensities are used to characterise the phenomena taking place in the interaction region. The ablation threshold of YBCO targets under 1.064 μm, 532 nm and 266 nm pulsed laser irradiation was evidenced with a photoacoustic method at 0.08–0.9 J/cm2, as a function of irradiation parameters (laser wavelength, spot area, target density). An estimation of the congruent ablation threshold is also proposed.